[flashrom] JtagKey-Tiny and SST25VF040B detected but read error.

[Carlos C]

Hi,

Sometimes flashrom identifies the flash chip but gives a "RDID byte 0 
parity violation". When the probing process ends without RDID error, the 
chip status register is incorrectly read as "BF".
After checking the eeprom board one hundred times, i've plugged a logic 
analizer into spi lines and logged two ID procceses, one with RDID error 
and the other with "BF" status register read.

This is the part of the probbing sequence related to SST25VF040B which 
gives "RDID byte 0 parity violation".
     flashrom -p ft2232_spi:type=jtagkey,port=A -V

    MISO Data     0x9F
         MOSI Data     0xBF
    MISO Data     0xFF
         MOSI Data     0x25
    MISO Data     0xFF
         MOSI Data     0x8D
    MISO Data     0xFF
         MOSI Data     0xFF
    MISO Data     0xAB
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xBF
    MISO Data     0x00
         MOSI Data     0x8D
    MISO Data     0x00
         MOSI Data     0xFF
    MISO Data     0x90
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xBF
    MISO Data     0x00
         MOSI Data     0x8D
    MISO Data     0x00
         MOSI Data     0xFF

And this one for the correct ID, but incorrectly read status register:
     flashrom -p ft2232_spi:type=jtagkey,port=A -V

    MISO Data     0x9F
         MOSI Data     0xBF
    MISO Data     0xFF
         MOSI Data     0x25
    MISO Data     0xFF
         MOSI Data     0x8D
    MISO Data     0xFF
         MOSI Data     0xFF
    MISO Data     0x05
         MOSI Data     0x1C
    MISO Data     0xFF
         MOSI Data     0x1C
    MISO Data     0xFF
         MOSI Data     0xFF
    MISO Data     0xAB
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xBF
    MISO Data     0x00
         MOSI Data     0x8D
    MISO Data     0x00
         MOSI Data     0xFF
    MISO Data     0x90
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xFF
    MISO Data     0x00
         MOSI Data     0xBF
    MISO Data     0x00
         MOSI Data     0x8D
    MISO Data     0x00
         MOSI Data     0xFF


As you can see, the difference starts after reading the ID (0xBF 0x25 
0x8D). Sometimes flashrom sends 0xAB, the eeprom answer with a chunk of 
0xFF's and shows a RDID error, and on some ocasions, it sends 0x05 to 
get the status register, so the eeprom answer 0x1C twice.

Appart from the RDID error, flashprog is reading 0xBF instead of 0x1C 
when asking for the status register. It seems to have some problem with 
FTDI buffers or something related, because the electric communication is 
perfect. The flash chip is answering as expected.

Any idea?

Regards,
Carlos


On 16/12/10 22:56, Carlos C wrote:
> Hi,
>
> I'm testing an Amontec JtagKey-tiny interface for programming a 
> SST25VF040B eeprom i'm using in a project.
> The Jtagkey-tiny is detected without problems, it reads the eeprom ID 
> and is detected.
>
> But when i try to read it contents, i get an error:
>
>     $ ./flashrom -p ft2232_spi:type=jtagkey,port=A -Vr test.bin
>     flashrom v0.9.3-r1205 on Linux 2.6.32-26-generic (i686), built
>     with libpci 3.0.0, GCC 4.4.3, little endian
>     flashrom is free software, get the source code at
>     http://www.flashrom.org
>
>     Calibrating delay loop... OS timer resolution is 2 usecs, 1000M
>     loops per second, 10 myus = 11 us, 100 myus = 91 us, 1000 myus =
>     904 us, 10000 myus = 9823 us, 8 myus = 10 us, OK.
>     Initializing ft2232_spi programmer
>     Using device type Amontec JTAGkey interface A
>     Set clock divisor
>     SPI clock is 2.000000MHz
>     No loopback of TDI/DO TDO/DI
>     Set data bits
>     [Probings ommited]
>     Probing for SST SST25VF040B, 512 KB: probe_spi_rdid_generic: id1
>     0xbf, id2 0x258d
>     Chip status register is bf
>     Chip status register: Block Protect Write Disable (BPL) is set
>     Chip status register: Auto Address Increment Programming (AAI) is
>     not set
>     Chip status register: Bit 5 / Block Protect 3 (BP3) is set
>     Chip status register: Bit 4 / Block Protect 2 (BP2) is set
>     Chip status register: Bit 3 / Block Protect 1 (BP1) is set
>     Chip status register: Bit 2 / Block Protect 0 (BP0) is set
>     Chip status register: Write Enable Latch (WEL) is set
>     Chip status register: Write In Progress (WIP/BUSY) is set
>     Resulting block protection : all blocks
>     Found chip "SST SST25VF040B" (512 KB, SPI) at physical address
>     0xfff80000.
>     [More probings ommited]
>     [UNTESTED status warning ommited]
>     Some block protection in effect, disabling
>     Missing status register write definition, assuming EWSR is needed
>     Reading flash... ftdi_write_data: -110, usb bulk write failed
>     send_buf failed at end: 1
>     Read operation failed!
>     FAILED.
>
> As you can see, i tried to low the SPI speed to 2MHz.
> Any idea? I know this part is marked as UNTESTED, but it should work 
> as SST25VF080B do.
>
> Thanks,
> Carlos
>

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